Confused About CRS in Civil 3D (Ireland): IRENET95/ITM vs. IRENET95/ITM 1995 with ETRS89 Datum

[Michael_gonzalez86NZM]

Hi everyone,

I'm having some trouble understanding Coordinate Reference Systems (CRS) in Civil 3D, and I hope someone can clarify this for me. Specifically, I’m confused about the difference between these two CRS options in the system:

• IRENET95 / Irish Transverse Mercator (ITM)
• IRENET95 / Irish Transverse Mercator 1995 with ETRS89 Datum

Both seem very similar, and I’m unsure what distinguishes them or if one is more accurate or up-to-date for use in Ireland. Could anyone explain the practical differences or recommend which one to use for infrastructure projects?

Thanks in advance for your help!

[Pointdump · Accepted solution]

Hi Michael,
I only see code "ITM". Where are you seeing these 2 CRS's?
In MAPCSLIBRARY, IRENET95_to_WGS84 is a null transformation. WGS84_to_ETRS89 is also a null transformation.
I can find no EPSG definition of ITM with the ETRS89 Datum. So I'd use >>>EPSG:2157, IRENET95/Irish Transverse Mercator<<<. Search "2157" in MAPCSLIBRARY.
Dave

[Michael_gonzalez86NZM]

Amazing.

Thanks Dave!